• 제목/요약/키워드: Geometric algorithm

검색결과 889건 처리시간 0.027초

SOME PROPERTIES OF SCHENSTED ALGORITHM USING VIENNOT'S GEOMETRIC INTERPRETATION

  • Lee, Jaejin
    • Korean Journal of Mathematics
    • /
    • 제21권3호
    • /
    • pp.223-236
    • /
    • 2013
  • Schensted algorithm was first described in 1938 by Robinson [5], in a paper dealing with an attempt to prove the correctness of the Littlewood-Richardson rule. Schensted [9] rediscovered Schensted algorithm independently in 1961 and Viennot [12] gave a geometric interpretation for Schensted algorithm in 1977. In this paper we describe some properties of Schensted algorithm using Viennot's geometric interpretation.

PFA의 기하 왜곡 보정 기법 (The Correcting Algorithm on Geometric Distortion of Polar Format Algorithm)

  • 이한길;김동환;손인혜
    • 한국군사과학기술학회지
    • /
    • 제21권1호
    • /
    • pp.17-24
    • /
    • 2018
  • Polar fomat algorithm (PFA) was derived from medical imaging theory, known as back projection, to process synthetic aperture radar(SAR) data. The difference between the operating condition of SAR and back projection assumption makes two distortions. First, the focusing performance of PFA is degraded in proportion to distances from the scene center. Second, the geometric accuracy in SAR images is distorted. Several methods were introduced to mitigate the distortions, but some disadvantages, such as the geometric discontinuity, are arisen when sub-images are combined. This paper proposes the novel method to compensate the geometric distortion with chirp Z-transform (CZT). This method corrects precisely the geometric errors without any problems, because a whole image can be processed all at once.

다중 사용자 OFDM 시스템을 위한 효율적이고 빠른 비트 배정 알고리즘 (An Efficient and Fast Bit Allocation Algorithm for Multiuser OFDM Systems)

  • 김민석;이창욱;전기준
    • 대한전기학회:학술대회논문집
    • /
    • 대한전기학회 2004년도 학술대회 논문집 정보 및 제어부문
    • /
    • pp.218-220
    • /
    • 2004
  • Orthogonal frequency division multiplexing(OFDM) is one of the most promising technique for next generation wireless broadband communication systems. In this paper, we propose a new bit allocation algorithm in multiuser OFDM. The proposed algorithm is derived from the geometric progression of the additional transmit power of subcarriers and the arithmetic-geometric means inequality. The simulation shows that this algorithm has similar performance to the conventional adaptive bit allocation algorithm and lower computational complexity than the existing algorithms.

  • PDF

The Exponentiated Weibull-Geometric Distribution: Properties and Estimations

  • Chung, Younshik;Kang, Yongbeen
    • Communications for Statistical Applications and Methods
    • /
    • 제21권2호
    • /
    • pp.147-160
    • /
    • 2014
  • In this paper, we introduce the exponentiated Weibull-geometric (EWG) distribution which generalizes two-parameter exponentiated Weibull (EW) distribution introduced by Mudholkar et al. (1995). This proposed distribution is obtained by compounding the exponentiated Weibull with geometric distribution. We derive its cumulative distribution function (CDF), hazard function and the density of the order statistics and calculate expressions for its moments and the moments of the order statistics. The hazard function of the EWG distribution can be decreasing, increasing or bathtub-shaped among others. Also, we give expressions for the Renyi and Shannon entropies. The maximum likelihood estimation is obtained by using EM-algorithm (Dempster et al., 1977; McLachlan and Krishnan, 1997). We can obtain the Bayesian estimation by using Gibbs sampler with Metropolis-Hastings algorithm. Also, we give application with real data set to show the flexibility of the EWG distribution. Finally, summary and discussion are mentioned.

스위핑과 불리언 연산에 대한 형상 구속조건 관리 (Geometric Constraint Management for Sweeping and Boolean Operations)

  • 김웅주;정채봉;김재정
    • 한국CDE학회논문집
    • /
    • 제5권4호
    • /
    • pp.301-311
    • /
    • 2000
  • For effective part modifications which is necessary in the design process frequently, variational geometric modeling with constraint management being used in a wide. Most variational geometric modeling methods, however, manage just the constraints about sketch elements used for generation of primitives. Thus, not only constraint propagation but also re-build of various modeling operations stored in the modeling history is necessary iota part geometry modifications. Especially, re-build of high-cost Boolean operations is apt to deteriorate overall modeling efficiency abruptly. Therefore, in this paper we proposed an algorithm that can handle all geometric entities of the part directly. For this purpose, we introduced eight type geometric constraints to the various geometric calculations about all geometric entities in sweepings and Boolean operations as well as the existing constraints of the sketch elements. The algorithm has a merit of rapid part geometric modifications through only constraint propagation without rebuild of modeling operations which are necessary in the existing variational geometric modeling method.

  • PDF

FXLMS 알고리즘 수렴성의 기하학적 해석 (Geometric Analysis of Convergence of FXLMS Algorithm)

  • 강민식
    • 대한전기학회논문지:시스템및제어부문D
    • /
    • 제54권1호
    • /
    • pp.40-47
    • /
    • 2005
  • This paper concerns on Filtered-x least mean square (FXLMS) algorithm for adaptive estimation of feedforward control parameters. The conditions for convergence in ensemble mean of the FXLMS algorithm are derived and the directional convergence properties are discussed from a new geometric vector analysis. The convergence and its directionality are verified along with some computer simulations.

Geometric charts with bootstrap-based control limits using the Bayes estimator

  • Kim, Minji;Lee, Jaeheon
    • Communications for Statistical Applications and Methods
    • /
    • 제27권1호
    • /
    • pp.65-77
    • /
    • 2020
  • Geometric charts are effective in monitoring the fraction nonconforming in high-quality processes. The in-control fraction nonconforming is unknown in most actual processes; therefore, it should be estimated using the Phase I sample. However, if the Phase I sample size is small the practitioner may not achieve the desired in-control performance because estimation errors can occur when the parameters are estimated. Therefore, in this paper, we adjust the control limits of geometric charts with the bootstrap algorithm to improve the in-control performance of charts with smaller sample sizes. The simulation results show that the adjustment with the bootstrap algorithm improves the in-control performance of geometric charts by controlling the probability that the in-control average run length has a value greater than the desired one. The out-of-control performance of geometric charts with adjusted limits is also discussed.

Weighted Carlson Mean of Positive Definite Matrices

  • Lee, Hosoo
    • Kyungpook Mathematical Journal
    • /
    • 제53권3호
    • /
    • pp.479-495
    • /
    • 2013
  • Taking the weighted geometric mean [11] on the cone of positive definite matrix, we propose an iterative mean algorithm involving weighted arithmetic and geometric means of $n$-positive definite matrices which is a weighted version of Carlson mean presented by Lee and Lim [13]. We show that each sequence of the weigthed Carlson iterative mean algorithm has a common limit and the common limit of satisfies weighted multidimensional versions of all properties like permutation symmetry, concavity, monotonicity, homogeneity, congruence invariancy, duality, mean inequalities.

AN ALGORITHM FOR CIRCLE FITTING IN ℝ3

  • Kim, Ik Sung
    • 대한수학회논문집
    • /
    • 제34권3호
    • /
    • pp.1029-1047
    • /
    • 2019
  • We are interested in the problem of determining the best fitted circle to a set of data points in space. This can be usually obtained by minimizing the geometric distances or various approximate algebraic distances from the fitted circle to the given data points. In this paper, we propose an algorithm in such a way that the sum of the squares of the geometric distances is minimized in ${\mathbb{R}}^3$. Our algorithm is mainly based on the steepest descent method with a view of ensuring the convergence of the corresponding objective function Q(u) to a local minimum. Numerical examples are given.

퍼지 알고리즘을 이용한 평면연삭의 형상정도 향상에 관한 연구 (A Sutdy on Improvement of Geomeric Accuracy by using Fuzzy Algorithm in Surface Grinding)

  • 천우진;김남경;하만경;송지복
    • 한국정밀공학회:학술대회논문집
    • /
    • 한국정밀공학회 1993년도 추계학술대회 논문집
    • /
    • pp.149-154
    • /
    • 1993
  • In heavy grinding that is on of the high efficient grinding method, meaningful deformation is generated by high temperature. So, after machining, geomeric error generated od the workpiece. The most important factor on the geometric error is temperature difference between upper layer and lower layer (T $_{d}$) . Relations between Td and grinding condition and maximum geometric error and grinding condition are obtained by experiment. This relations are used in fuzzy algorithm for improvement geometric accuracy. The main results are follows : (1) The linear relation between maximum geometric error and grinding condition is ovtained by experiment. (2) The linear relation between maximum temperature difference between upper layer and lower layer and grinding condition is ovtained by experiment. (3) Control peth of wheel for improvement geometric accuracy is obtained by using the fuzzy algorithm.m.

  • PDF